240 NEW RED SANDSTONE. 



undoubtedly Keuper, passing gradually into the Rhcetic Beds east 

 of Axmouth. As Mr. Pengelly first pointed out, there is no uncon- 

 formity in the series, and no doubt the Muschelkalk is represented 

 here, as elsewhere in point of time, although it is hazardous to 

 say by which beds in particular. (See pp. 221, 233.) 



Econo7nic products, etc., of the Keuper Beds} 



The Sandstones have been largely quarried for building-purposes at Ombersley 

 and Hadley, near Droitwich. In the neighbourhood of Pattingham and Tatten- 

 hall the Basement beds have been burnt for hme. In the Havvkstone range in 

 Shropshire, and at Grinshill north of Shrewsbury, the Lower Keuper sandstones 

 have yielded good freestones, and thin flags sometimes used for roofing. They 

 are quarried at Delamere, Peckforton, and other places in Cheshire ; near 

 Ashbourne, in Derbyshire ; and at Alton and Hollington, in Staffordshire. The 

 Basement beds yield the best building-stones of the Trias. Among the local 

 stones may be mentioned the Bank Delf Stone of Bank Quarry, Melling, 

 near Ormskirk ; the Runcorn stone ; the beds at Drayton Basset, south-west 

 of Tamworth ; and the Kingwood Stone in the neighbourhood of Codsall. 



The Lower Keuper sandstones of Alderley Edge and Mottram St. Andrew 

 have yielded much copper-ore, together with galena and cobalt-ore. Traces of 

 copper-ore have also been met with at Grinshill, on the east side of the Peckforton 

 Hills.2 



In Cheshire and Worcestershire extensive beds of Rock-salt occur, interstratified 

 with the lower beds of the Keuper Marl. Our culinary salt is largely manufactured 

 from the brine-springs ; hence the term ' Saliferous ' is sometimes applied to the 

 Upper Keuper strata. 



Among the localities for rock-salt or brine-springs are Droitwich and Stoke, in 

 Worcestershire ; Northwich, Sandbach, Anderton, Middlewich, Wheelock, Wins- 

 ford, Lawton, Dirtwich, Foulwich, and Nantwich in Cheshire ; Adderley in 

 Shropshire, and Shirleywich in Staffordshire. At Droitwich, and also at 

 Nantwich, Middlewich, and Northwich, on the banks of the Weaver, the salt has 

 been extracted from the brine for upwards of 1000 years. The rock-salt was 

 accidentally found in 1670 in sinking a coal-pit at Marbury, near Northwich.^ 



The brine-springs yield about 25 per cent, of chloride of sodium, the water 

 being pumped to the surface ; they now furnish the chief supply, the total amount 

 of rock-salt mined being about 150,000 tons annually, while that obtained from 

 brine was 1,800,000 tons in 1880. The Rock-salt occurs sometimes in a massive or 

 granular form, at others in large cubical crystals ; Gypsum is often found with it. 

 The former is usually of a dull red tint, and associated with red and pale green 

 marls, and with greenish-grey splintery shale. 



At Winsford, Northwich, and other places in Cheshire, where the salt is worked, 

 the beds containing it are reached at a depth of from 50 to 160 yards below the 

 surface. The number of saliferous beds in the district is five, they vary in 

 thickness from a few inches to over 100 feet, and extend several hundred feet 

 where proved. A considerable quantity of salt is also mixed with the marls 

 associated with the purer beds. The descent to the mines is by a shaft, used for 

 the general purposes of drainage, ventilation, etc. The roof, which is about twenty 

 feet above the floor, is supported by pillars about fifteen feet in width. When 



^ In many instances, especially in parts relating to the south-west of England, 

 the economic products have been previously mentioned. 



2 E. Hull, G. Mag. 1864, p. 65 ; Geology of Stockport, etc., p. 39. 



2 G. Ormerod, Hist, of Cheshire, i. p. xlvi. See also H. Holland, Agric. of 

 Cheshire, 1808 ; and Trans. G. S. i. 38 ; L. Horner, T. G. S. ii. 94 ; C. Parkin- 

 son, Q.J. xl. 248; Hull, Geology of Altrincham, Cheshire; T. Ward, Mem. 

 Lit. and Phil. Soc. Manchester, 1881-2 ; G. W. Ormerod, Q. J. ix. 187. 



